1. Field of the Invention
The present invention relates to a photographing system and a motion picture camera using the same, which can selectively use a silent film cartridge housing a film which can record picture image only and a simultaneous sound recording film cartridge housing a film which can simultaneously record picture image and sound.
2. Description of the Prior Art
Recently, while a cartridge type film for picture image recording which is simple for handling and eliminating light leakage is widely used in a field of a small size motion picture, a cartridge film convenient for handling which can simultaneously record a picture image and sound has not been put into practical use.
However, present requirements for such a system which allows simple recording of a picture and sound on the same recording material are increasing more and more, and specifications of U.S. Pat. Nos. 3,561,851 and 3,604,790, etc. are known to disclose the same.
As the film cartridge housing a film allowing simple recording of a picture and sound on the same film, a film cartridge which has almost the same cartridge shape as a silent film cartridge housing a silent film being able to record a picture image only and being known generally as "Super 8", and has only one portion thereof being enlarged, is known. In a camera using a sound film cartridge housing a film which is able to record a picture and sound, a conventional silent film cartridge for picture recording only can be used also, and while a conventional camera which can use a silent film cartridge only has only a picture image recording mechanism, a motion picture camera, which can selectively use a silent film cartridge and a sound film cartridge and can record picture image and sound informations on the film when the sound film cartridge is loaded, has a sound recording mechanism besides the picture image recording mechanism. And as a method by which this sound recording mechanism record sound information signal on the sound recording part of the film, optical sound recording or magnetic sound recording, in which magnetic body is provided at the sound recording part of the film and making magnetic sound recording using a magnetic head at the magnetic body, is used, where by either method constant speed feeding of film is required at the sound recording means part to record sound for stabilizing sound quality. For this purpose, a constant speed film feeding mechanism by a capstan and a pinch roller is used frequently besides a film advancing mechanism for picture image photographing, and an elastic body of rubber type is used as the material for the pinch roller. Therefore, because the pinch roller is placed in a state where it is pressed against the capstan for a long time it is apt to have plastic deformation, and as plastic deformation takes place it causes difficulties in constant speed feeding of the film. Therefore, it is effective, in a motion picture camera allowing simultaneous recording of picture image and sound as mentioned above, to employ such a mechanism as having engagement and disengagement of a pinch roller with a capstan linked with shutter release action of the camera, thereby having the pinch roller pressed against the capstan only during photographing and having the pinch roller separated from the capstan when not in use. In this kind of a motion picture camera having such consideration, a pinch roller is provided at a position slightly separated from a capstan under normal conditions and the pinch roller is pressed against the capstan by a spring which is biased by release action. Therefore it has such shortcoming that an operator is required to use strong power to bias the spring of the pinch roller besides the light operating power required for ordinary release action. Since the strong operating power needs to be retained all through the photographing, when the photographer makes long time photographing operation, his finger, etc. operating the release is very likely to tire.
Also, in this kind of motion picture camera, usually silent photographing only for picture image is also possible using a silent film cartridge having no sound recording belt, and at the time of this silent photographing, not only the sound recording mechanism but the pinch roller action linked with release action is not necessary. Therefore, it causes loss not only in durability of the mechanism but in power to operate a capstan driving motor for a constant speed film feeding mechanism and the sound recording mechanism during the silent photographing. Also, the fact that the pinch roller pressing action is done each time release action is preformed, creates the difficulty wherein release action, which can be normally light, unnecessarily heavy even in silent photographing because the camera has the sound recording mechanism and the constant speed film feeding mechanism, and the life of the pinch roller, etc. will therefore be short.